STMicroelectronics LD1086V80

Overview

LD1086V80 from STMicroelectronics is a fixed-output 8.0 V, 1.5 A low-dropout linear voltage regulator in TO-220 package, designed for post-regulation in industrial power supplies and embedded systems requiring stable output under high load and wide input range (up to 30 V). It delivers ±1% output tolerance at 25 °C, 1.3 V typical dropout at full load, and integrates thermal shutdown and internal current limiting.

For engineers reviewing the LD1086V80 datasheet, LD1086V80 pinout, LD1086V80 application, or LD1086V80 equivalent, key selection criteria include dropout performance at 1.5 A, output stability across –40 °C to +125 °C, minimum external capacitance (10 µF), and compatibility with legacy 3-terminal adjustable regulator footprints.

Technical Context

The LD1086V80 uses a PNP-based pass transistor architecture with on-chip trimming for tight output voltage accuracy. Its reference voltage is internally set to 1.25 V, enabling fixed 8.0 V output via resistor-free configuration. Dropout behavior is monotonic and guaranteed ≤1.5 V up to 1.5 A across temperature.

Quiescent current flows entirely into the load-not wasted as bias-improving efficiency versus traditional PNP regulators. Internal protection includes thermal foldback and short-circuit current limiting, with no external components required for basic operation beyond input/output capacitors.

Key Specifications

Pinout & Package

LD1086V80 is supplied in TO-220 package (STD-ST dual gauge type A) with electrically connected metal tab tied to OUTPUT pin for direct heatsink mounting. Pin 1 = INPUT, Pin 2 = OUTPUT (tab), Pin 3 = GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Compared with LD1086V80R, the TO-220 version offers superior thermal dissipation for sustained 1.5 A loads without complex PCB thermal design; versus TLV1117-80, it delivers 88% higher current capability and twice the output accuracy-critical for industrial and medical applications demanding long-term stability.

Availability

LD1086V80 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, medical diagnostic equipment, and test & measurement instruments requiring stable component supply with full production lifecycle support.

Supply support for LD1086V80 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, microcontrollers, and automotive ICs with vertical manufacturing capabilities.

The LD1086 series belongs to ST's high-current linear regulator product line, engineered for robustness in harsh environments and designed to replace legacy adjustable regulators while delivering tighter tolerance, lower dropout, and improved thermal performance.

FAQ

Is LD1086V80 pin-compatible with LM317?

No-LM317 is adjustable and uses ADJ/OUT/GND pinout, while LD1086V80 is fixed 8 V with IN/OUT/GND. However, LD1086V80 matches the footprint and pin function of older fixed-output regulators like LM7808, not LM317. Its "pin-to-pin compatible with standard adjustable regulators" refers to mechanical layout similarity (3-pin TO-220), not electrical equivalence.

What is the minimum input voltage required for regulation at 1.5 A?

The minimum input voltage is 9.3 V: 8.0 V output + 1.3 V typical dropout. At 1.5 A and 125 °C, maximum dropout is 1.5 V, so 9.5 V input is recommended for margin. Below this, output voltage sags and regulation is lost.

Can LD1086V80 be used without an input capacitor?

No-an input capacitor (≥10 µF) is mandatory for stability and transient response. Without it, the regulator may oscillate or fail to reject line noise, especially with long input traces or high-impedance sources. Ceramic or tantalum types are preferred.

Does the metal tab connect to output or ground?

The metal tab is electrically connected to the OUTPUT pin (Pin 2), not ground. This is confirmed in the datasheet note: "The TAB is physically connected to the output (this is valid for the TO-220 package too)." Heatsinks must be insulated unless referenced to the 8 V rail.